The present invention relates generally to uterine sound devices for measuring the depth and course of a uterus and more specifically relates to flexible, disposable, polyvinyl chloride-coated uterine sound devices.
In the gynecological field, it is sometimes necessary for a physician to measure the internal cavity of a uterus. For instance, such measurements may be necessary to ascertain the depth and course of an uterine cavity to prevent the accidental perforation of the uterus during a subsequent surgical procedure. In some instances such measurements may be performed both before and after a surgical procedure to insure that the uterus has properly contracted upon completion of a procedure.
Most uterine sound devices that are currently in use are reusable devices. Generally, these devices are silver-plated copper rods with graduations engraved in the surface of the rod to indicate units of length along the rod. Such devices have several disadvantages. For instance, since the devices are formed by plating silver onto copper, the resulting silver plating may gradually wear off leaving the copper exposed to the patient as the devices are repeatedly reused. This is a disadvantage because the copper can be potentially harmful to the patient. Thus, it is necessary for medical personnel to continuously monitor such devices to be sure that the silver-plating is still intact. Also, silver-plated uterine sound devices have the disadvantage that medical personnel must be careful when cleaning the devices to prevent the accidental removal of the silver plating.
Another disadvantage of such sound devices is the fact that by engraving the graduations on to the device, the engraved portions of the device can exacerbate trauma to the patient as the device is introduced into the cervix. In fact, in the past, such indentions have been intentionally used to collect blood as the sound device is removed to provide the physician a point of reference on the surface of the sound to determine the depth of the uterus.
While some reusable sound devices have a degree of flexibility and malleability, it is desired to provide a device which has greater flexibility and malleability than the currently available products. Flexibility is important because it can reduce the possibility of accidental perforation of the uterus as a physician reaches the uterine wall. A degree of flexibility is a desirable feature because it allows the sound device to flex slightly when the wall of the uterus is reached thereby putting the physician on notice that further pressure may cause a perforation. Malleability of a uterine sound device is a desirable feature because it also prevents the possibility of accidental perforation. Typically, before a sound device is inserted, the physician has performed a pelvic examination to determine if the uterus is anteverted, retroverted or in any other position. If the sound device is sufficiently malleable, the physician may then bend the device so that it generally conforms to the presumed course of the uterine cavity. Thus, as the device is inserted, it is more likely to follow the natural course of the uterine cavity and it is consequently less likely to perforate the uterine wall. If the sound device is too flexible or too malleable, it may not be able to maintain its desirable shape during insertion which will limit a physician's ability to accurately assess the position of the sound within the uterine cavity.
Disposable uterine sound devices have also been used in the past. Generally, these devices are made entirely of plastic. These devices are similar to the non-disposable uterine sound devices in that the graduations are imprinted onto the device. Thus, the outer surface of the device can still induce unnecessary trauma to a patient during insertion and removal. In some disposable uterine sound devices, flexibility has been created by producing a series of notches in the devices to allow the devices to bend. While these notches provide flexibility, they are disadvantageous in that they can also cause unnecessary trauma and limit the ability of the device to maintain its shape after it has been bent.